How Intense Is Your Workout?

Light, moderate, or vigorous. When it comes to exercising, which do you choose?

Although you might think that exercise must be vigorous to be healthy, moderate exercise can provide many of the same health benefits. And if you haven't been active in a while, light exercise may be enough of a challenge for you at first.

How can you measure the intensity of your exercise? The CDC says that there are several ways to determine your exercise intensity. Remember to check with your health care provider before starting any new exercise program.

Talk test

This is a simple method of determining intensity. The CDC says that at a light level of exercise, you should be able to sing while doing the activity. If your level of exercise is moderate, you should be able to talk, but not sing. If your level of exercise is vigorous, you will not be able to say a few words without pausing for a breath.

Heart rate

Another way to determine the intensity of your workout is to find out if your heart rate, or pulse, is within the target zone, advises the CDC. First, figure your maximum heart rate by subtracting your age from 220. For instance, if you are 35, your maximum heart rate is 220 minus 35, or 185 beats per minute. For moderate-intensity exercise, your heart rate should fall between 50 and 70 percent of your maximum heart rate. For a 35-year-old, that would be 93 to 130 beats per minute. For a 50-year-old, the maximum heart rate would be 170 beats per minute, with moderate-intensity exercise level at 85 to 119 beats per minute.

Here's a breakdown of workout intensity and heart rate:

A light workout is at less than 50 percent of your maximum heart rate.

A moderate-intensity workout is 50 to 70 percent of your maximum heart rate.

A vigorous workout is 70 to 85 percent of your maximum heart rate.

To find out if your heart rate is in the target zone while you're exercising, you must stop briefly in order to take your pulse. Place your index and middle finger lightly on your wrist, the CDC says. Start counting on a beat, which is counted as zero. Count for 60 seconds, or 30 seconds and multiply by 2.

Other methods

Another method measures exercise intensity by the metabolic equivalent (MET) level, the CDC says. MET estimates the amount of oxygen used by the body during activity. For instance, one MET is the amount of oxygen you use when sitting quietly. The more intense the exercise, the higher the MET level. Moderate-intensity exercise burns 3 to 6 METs. Vigorous exercise burns more than 6 METs.

Which exercises to choose?

Even the light-intensity exercises below can increase in intensity if you do them for a longer time. Intensity increases with time, the CDC says. If you walk slowly or do light gardening, you can increase the intensity of those activities by doing them for at least an hour. Compare those activities with swimming laps or playing singles tennis, both of which are rated as vigorous exercise. You achieve the same level of intensity for these in 20 to 30 minutes, versus an hour for light exercise.